Hum, variance ?
Obviously his line doesn't make any sense to us no matter what he has, so talking about ranges will prove to be difficult. Go with the maths since it's unlikely he has you beat already at this point and call it off. If you don't like taking those gambles on his state of mind or abhor variance, just dump it, nobody is looking over your shoulder to tell you how nitty that fold is

Some other factors you might want to consider are

* How did he get that 160bb stack ? Anything you can assume on his play from the way he built it ?

* Did you ever see that guy bet or raise before ? Did his betsizing make sense then ? If not, just call it off. If yes, why would he overbet here ?

* Have you seen him play a draw passively before, making it unlikely he would do that with a flushdraw ?

* Have you been isolating him and taking pots down with a c-bet often since you got here ? Could he be sick of you already ? I've seen guys shove KK in those spots, trying to slowplay and when they're just tired of flopping overcards and having to fold to other people's c-bet, sometimes they just go off.